Typically, during an emergency evacuation of a building, occupants must make their own assessment regarding the relative safety of possible egress routes and select a route that they perceive as safe. Under the stress of time pressure and uncertainty, an occupant's assessment and choice of safety route may be faulty. Frequently, the default choice made by an occupant involves either evacuating along the same route that he or she used to enter the building that day, or moving toward a known fixed emergency exit that may or may not be safe. Adaptive evacuation systems offer the potential to relieve the occupant of these difficult egress decisions.
In conditions where it is difficult to find a safe path out of a building, indications as to which of the escape routes is/are safe and indications of how to get to that escape route can be very valuable. In more severe emergencies such as earthquakes, parts of a building may have collapsed. This severe damage can block the path to safe egress routes. Further, any changes in the building due to a collapse can combine with smoke and dust to become very disorienting.
In a severe fire, the whole process of searching for safety evacuation routes may become even more difficult if thick smoke fills the entire structure. In a severe fire, evacuee panic can combine with obscuration by heavy smoke to create severe disorientation in the evacuees. These difficulties can be further aggravated if the fire spreads so rapidly that the escape routes are blocked or cut off by the fire.
In conditions where it might be difficult to find a safe way out of a building, indications of where the safe egress routes are located would be very helpful. On the other hand, first responders, especially fire fighters, often have considerable difficulty in navigating through buildings during an emergency. Fire fighters have a difficult time determining their location in the building, and where they can go when smoke is thick. Fire fighters often do not know the building layout well, and do not have accurate information for navigating toward an identified location. As a result the fire fighter can be become lost. Fire fighters also often have a difficult time finding multiple objectives such as the fire, standpipes, and the suspected locations of victims, who must be found quickly.
It is important for fire fighting crews to go directly to the fire when they arrive at a fire scene. Even if the location of the fire is known, getting to the fire can be a challenging task due to a lack of knowledge of the building layout. Fire fighters also need other important information such as the need to travel to water supplies, victims, or special hazards.